PTSD, subsequent violence, and increased focus on trauma-informed care
Authors: Märta Wallinius, Thomas Nilsson
Journal: The Lancet Public Health (2023)

Violence is a global public health priority affecting the lives of people worldwide, either as victims, perpetrators, or members of society.1Dahlberg LL Krug EG Violence: a global public health problem.Cien Saude Colet. 2006; 11: 277-292Crossref Scopus (58) Google Scholar It can lead to traumatic experiences, and studies of military personnel have linked post-traumatic stress disorder (PTSD) to subsequent violent behaviours,2Ramchand R Schell TL Karney BR Osilla KC Burns RM Caldarone LB Disparate prevalence estimates of PTSD among service members who served in Iraq and Afghanistan: possible explanations.J Trauma Stress. 2010; 23: 59-68Crossref PubMed Scopus (240) Google Scholar indicating a potential bidirectional association between trauma exposure and violence. These effects are especially pertinent in relation to war.3Macmanus D Dean K Al Bakir M et al.Violent behaviour in UK military personnel returning home after deployment.Psychol Med. 2012; 42: 1663-1673Crossref PubMed Scopus (94) Google Scholar Furthermore, traumatic experiences during childhood have been linked to subsequent violence and substantial health challenges for individuals.4Hughes K Bellis MA Hardcastle KA et al.The effect of multiple adverse childhood experiences on health: a systematic review and meta-analysis.Lancet Public Health. 2017; 2: e356-e366Summary Full Text Full Text PDF PubMed Google Scholar In familial contexts, these subsequent effects have been referred to as a cycle of violence.5Widom CS The cycle of violence.Science. 1989; 244: 160-166Crossref PubMed Google Scholar However, there are few studies investigating mental disorders related to the substantial and long-term effects of trauma, such as PTSD, in relation to violence, and findings from the existing studies have methodological limitations. In this issue of The Lancet Public Health, Anabelle Paulino and colleagues6Paulino A Kuja-Halkola R Fazel S et al.Post-traumatic stress disorder and the risk of violent crime conviction in Sweden: a nationwide, register-based cohort study.Lancet Public Health. 2023; 8: e432-e441Summary Full Text Full Text PDF Google Scholar use a Swedish general population sample with matched controls and sibling comparisons from linked registry data to show that, regardless of previous psychiatric comorbidity and familial factors, PTSD is associated with an increased risk of violent crime conviction (hazard ratio [HR] 6·4, 95% CI 5·7–7·2). However, they also show that substance use disorder (SUD) and a history of violent crime, both prominent risk factors for violent offending, confound this association, as was shown when analyses were stratified by history of violent crime (2·2, 1·7–3·0) and SUD (1·9, 1·5–2·6). Although these results imply a risk increase at the population level for violent crime in people diagnosed with PTSD who do not have previous SUD or a history of violent crime, possible moderation or mediation effects remain unclear. Observational studies of registry data can be informative and include broader perspectives on public health challenges, especially when conducted in settings with high coverage and validity of national registers. Such studies are statistically well powered, have general representativeness for the investigated setting, and use objective measures (eg, official records) instead of subjective measures (eg, self-report). However, the inherent limitations of this design include requirements for a disorder or behaviour to be registered in official records. The main outcome in this study, violent crime conviction, has been described as largely under-reported when used as an estimation of violent crime.7Steadman HJ Mulvey EP Monahan J et al.Violence by people discharged from acute psychiatric inpatient facilities and by others in the same neighborhoods.Arch Gen Psychiatry. 1998; 55: 393-401Crossref PubMed Scopus (1147) Google Scholar Reliance on official records might also have affected the prevalence of PTSD diagnoses. Qualitative research in the UK found a reluctance to seek health care for mental distress in male offenders.8Howerton A Byng R Campbell J Hess D Owens C Aitken P Understanding help seeking behaviour among male offenders: qualitative interview study.BMJ. 2007; 334: 303-306Crossref PubMed Google Scholar Thus, the magnitude of an association between PTSD and violent crime might not be adequately captured in studies using registry data only. These issues are acknowledged by the authors but should be considered when translating their results to health-care interventions. Another issue that affects all research on violent crime is the way basic concepts, such as diagnoses and violent crime, are defined. Long-term studies of individuals are susceptible to changes in diagnostic systems and laws over time. Applying broad definitions of violent crime, as was done by Paulino and colleagues, further adds to this susceptibility. For example, differing definitions of violence are common in the literature.9Harris ST Oakley C Picchioni M Quantifying violence in mental health research.Aggress Violent Behav. 2013; 18: 695-701Crossref Scopus (0) Google Scholar In future research, associations between PTSD and different forms of violence should be investigated in different, well assessed populations to establish whether PTSD pathophysiology could be related to specific circumstances or forms of violence, thus contributing to a better understanding of the mechanisms of the association and the development of preventive measures. Paulino and colleagues' study raises several questions that require continued investigation. The theoretical foundation for the study—violence as an expression of dysregulated stress-mediating biological systems in response to trauma—cannot be investigated by relying on registry data, but requires clinical studies in which individuals are followed up longitudinally with repeated measures during several so-called units of analysis.10Sanislow CA Pine DS Quinn KJ et al.Developing constructs for psychopathology research: research domain criteria.J Abnorm Psychol. 2010; 119: 631-639Crossref PubMed Scopus (542) Google Scholar With the current findings from Paulino and colleagues as a basis for investigations of trauma and stress regulation in relation to violence, establishing possible mechanisms of these associations will provide new possibilities for targeted interventions for individuals with trauma and violent behaviour. This study is an encouragement for the field of mental health to apply a trauma-informed perspective and take PTSD seriously as something to screen for and treat in clinical groups, especially forensic groups, with possible benefits both for mental health improvement and violence prevention in society. We declare no competing interests. Post-traumatic stress disorder and the risk of violent crime conviction in Sweden: a nationwide, register-based cohort studyPTSD was associated with increased risk of violent crime conviction, even after controlling for familial effects shared by siblings and in the absence of SUD or a history of violent crime. Although our results might not be generalisable to less severe or undetected PTSD, our study could inform interventions that aim to reduce violent crime in this vulnerable population. Full-Text PDF Open Access